/*
 *  ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
 *  ircd.c: Starts up and runs the ircd.
 *
 *  Copyright (C) 2002 by the past and present ircd coders, and others.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 *
 *  $Id: ircd.c 455 2006-09-08 20:53:08Z jon $
 */

#include "stdinc.h"
#include "s_user.h"
#include "tools.h"
#include "ircd.h"
#include "channel.h"
#include "channel_mode.h"
#include "client.h"
#include "common.h"
#include "event.h"
#include "fdlist.h"
#include "hash.h"
#include "irc_string.h"
#include "sprintf_irc.h"
#include "ircd_signal.h"
#include "list.h"
#include "s_gline.h"
#include "motd.h"
#include "ircd_handler.h"
#include "msg.h"		/* msgtab */
#include "hostmask.h"
#include "numeric.h"
#include "packet.h"
#include "parse.h"
#include "irc_res.h"
#include "restart.h"
#include "s_auth.h"
#include "s_bsd.h"
#include "s_conf.h"
#include "s_log.h"
#include "s_misc.h"
#include "s_serv.h"		/* try_connections */
#include "s_stats.h"
#include "send.h"
#include "whowas.h"
#include "modules.h"
#include "memory.h"
#include "hook.h"
#include "ircd_getopt.h"
#include "balloc.h"
#include "motd.h"
#include "supported.h"
#include "cloak.h"

/* Try and find the correct name to use with getrlimit() for setting the max.
 * number of files allowed to be open by this process.
 */

/* /quote set variables */
struct SetOptions GlobalSetOptions;

/* configuration set from ircd.conf */
struct config_file_entry ConfigFileEntry;
/* server info set from ircd.conf */
struct server_info ServerInfo;
/* admin info set from ircd.conf */
struct admin_info AdminInfo = { NULL, NULL, NULL };
struct Counter Count = { 0, 0, 0, 0, 0, 0, 0, 0 };
struct ServerState_t server_state = { 0 };
struct logging_entry ConfigLoggingEntry = { 1, {0}, {0}, {0}, {0}, {0}, {0}, {0}, {0} };
struct timeval SystemTime;
struct Client me;		/* That's me */
struct LocalUser meLocalUser;	/* That's also part of me */
unsigned long connect_id = 0;	/* unique connect ID */

static unsigned long initialVMTop = 0;	/* top of virtual memory at init */
const char *logFileName = LPATH;
const char *pidFileName = PPATH;

char **myargv;
char ircd_platform[PLATFORMLEN];

int dorehash = 0;
int doremotd = 0;
time_t nextconnect = 1;		/* time for next try_connections call */

/* Set to zero because it should be initialized later using
 * initialize_server_capabs
 */
int default_server_capabs = 0;

#ifdef HAVE_LIBCRYPTO
int bio_spare_fd = -1;
#endif

int splitmode;
int splitchecking;
int split_users;
unsigned int split_servers;
int svsnoop = 0;

/* Do klines the same way hybrid-6 did them, i.e. at the
 * top of the next io_loop instead of in the same loop as
 * the klines are being applied.
 *
 * This should fix strange CPU starvation as very indirectly reported.
 * (Why do you people not email bug reports? WHY? WHY?)
 *
 * - Dianora
 */

int rehashed_klines = 0;

/*
 * get_vm_top - get the operating systems notion of the resident set size
 */
#ifndef _WIN32
static unsigned long
get_vm_top(void)
{
	/*
	 * NOTE: sbrk is not part of the ANSI C library or the POSIX.1 standard
	 * however it seems that everyone defines it. Calling sbrk with a 0
	 * argument will return a pointer to the top of the process virtual
	 * memory without changing the process size, so this call should be
	 * reasonably safe (sbrk returns the new value for the top of memory).
	 * This code relies on the notion that the address returned will be an 
	 * offset from 0 (NULL), so the result of sbrk is cast to a size_t and 
	 * returned. We really shouldn't be using it here but...
	 */

	void *vptr = sbrk(0);
	return ((unsigned long) vptr);
}

/*
 * print_startup - print startup information
 */
static void
print_startup(int pid)
{
	printf("ircd: version %s(%s)\n", ircd_version, serno);
	printf("ircd: pid %d\n", pid);
	printf("ircd: running in %s mode from %s\n", !server_state.foreground ? "background"
	       : "foreground", ConfigFileEntry.dpath);
}

static void
make_daemon(void)
{
	int pid;

	if((pid = fork()) < 0)
	{
		perror("fork");
		exit(EXIT_FAILURE);
	}
	else if(pid > 0)
	{
		print_startup(pid);
		exit(EXIT_SUCCESS);
	}

	setsid();
}
#endif

/*
 * get_maxrss - get the operating systems notion of the resident set size
 */
unsigned long
get_maxrss(void)
{
#ifdef _WIN32
	return (0);		/* FIXME */
#else
	return (get_vm_top() - initialVMTop);
#endif
}

static int printVersion = 0;

struct lgetopt myopts[] = {
	{"dlinefile", &ConfigFileEntry.dlinefile,
	 STRING, "File to use for dline.conf"},
	{"configfile", &ConfigFileEntry.configfile,
	 STRING, "File to use for ircd.conf"},
	{"klinefile", &ConfigFileEntry.klinefile,
	 STRING, "File to use for kline.conf"},
	{"xlinefile", &ConfigFileEntry.xlinefile,
	 STRING, "File to use for xline.conf"},
	{"logfile", &logFileName,
	 STRING, "File to use for ircd.log"},
	{"pidfile", &pidFileName,
	 STRING, "File to use for process ID"},
	{"foreground", &server_state.foreground,
	 YESNO, "Run in foreground (don't detach)"},
	{"version", &printVersion,
	 YESNO, "Print version and exit"},
	{"help", NULL, USAGE, "Print this text"},
	{NULL, NULL, STRING, NULL},
};

void
set_time(void)
{
	static char to_send[200];
	struct timeval newtime;
#ifdef _WIN32
	FILETIME ft;

	GetSystemTimeAsFileTime(&ft);
	if(ft.dwLowDateTime < 0xd53e8000)
		ft.dwHighDateTime--;
	ft.dwLowDateTime -= 0xd53e8000;
	ft.dwHighDateTime -= 0x19db1de;

	newtime.tv_sec = (*(uint64_t *) & ft) / 10000000;
	newtime.tv_usec = (*(uint64_t *) & ft) / 10 % 1000000;
#else
	newtime.tv_sec = 0;
	newtime.tv_usec = 0;

	if(gettimeofday(&newtime, NULL) == -1)
	{
		ilog(L_ERROR, "Clock Failure (%s), TS can be corrupted", strerror(errno));
		sendto_realops_flags(UMODE_ALL, L_ALL,
				     "Clock Failure (%s), TS can be corrupted", strerror(errno));
		restart("Clock Failure");
	}
#endif

	if(newtime.tv_sec < CurrentTime)
	{
		ircsprintf(to_send, "System clock is running backwards - (%lu < %lu)",
			   (unsigned long) newtime.tv_sec, (unsigned long) CurrentTime);
		report_error(L_ALL, to_send, me.name, 0);
		set_back_events(CurrentTime - newtime.tv_sec);
	}

	SystemTime.tv_sec = newtime.tv_sec;
	SystemTime.tv_usec = newtime.tv_usec;
}

static void
io_loop(void)
{
	while(1 == 1)
	{
		/*
		 * Maybe we want a flags word?
		 * ie. if (REHASHED_KLINES(global_flags)) 
		 * SET_REHASHED_KLINES(global_flags)
		 * CLEAR_REHASHED_KLINES(global_flags)
		 *
		 * - Dianora
		 */
		if(rehashed_klines)
		{
			check_conf_klines();
			rehashed_klines = 0;
		}

		if(listing_client_list.head)
		{
			dlink_node *ptr = NULL, *ptr_next = NULL;
			DLINK_FOREACH_SAFE(ptr, ptr_next, listing_client_list.head)
			{
				struct Client *client_p = ptr->data;
				assert(client_p->localClient->list_task);
				safe_list_channels(client_p, client_p->localClient->list_task, 0,
						   0);
			}
		}

		/* Run pending events, then get the number of seconds to the next
		 * event
		 */
		while(eventNextTime() <= CurrentTime)
			eventRun();

		comm_select();
		exit_aborted_clients();
		free_exited_clients();
		send_queued_all();

		/* Check to see whether we have to rehash the configuration .. */
		if(dorehash)
		{
			rehash(1);
			dorehash = 0;
		}
		if(doremotd)
		{
			read_message_file(&ConfigFileEntry.motd);
			sendto_realops_flags(UMODE_ALL, L_ALL,
					     "Got signal SIGUSR1, reloading ircd motd file");
			doremotd = 0;
		}
	}
}

/* initalialize_global_set_options()
 *
 * inputs       - none
 * output       - none
 * side effects - This sets all global set options needed 
 */
static void
initialize_global_set_options(void)
{
	memset(&GlobalSetOptions, 0, sizeof(GlobalSetOptions));

	GlobalSetOptions.autoconn = 1;
	GlobalSetOptions.spam_time = MIN_JOIN_LEAVE_TIME;
	GlobalSetOptions.spam_num = MAX_JOIN_LEAVE_COUNT;

	if(ConfigFileEntry.default_floodcount)
		GlobalSetOptions.floodcount = ConfigFileEntry.default_floodcount;
	else
		GlobalSetOptions.floodcount = 10;

	/* XXX I have no idea what to try here - Dianora */
	GlobalSetOptions.joinfloodcount = 16;
	GlobalSetOptions.joinfloodtime = 8;

	split_servers = ConfigChannel.default_split_server_count;
	split_users = ConfigChannel.default_split_user_count;

	if(split_users && split_servers && (ConfigChannel.no_create_on_split ||
					    ConfigChannel.no_join_on_split))
	{
		splitmode = 1;
		splitchecking = 1;
	}

	GlobalSetOptions.ident_timeout = IDENT_TIMEOUT;
	GlobalSetOptions.idletime = ConfigFileEntry.idletime;
	/* End of global set options */
}

/* initialize_message_files()
 *
 * inputs       - none
 * output       - none
 * side effects - Set up all message files needed, motd etc.
 */
static void
initialize_message_files(void)
{
	init_message_file(USER_MOTD, MPATH, &ConfigFileEntry.motd);
	init_message_file(OPER_MOTD, OPATH, &ConfigFileEntry.opermotd);
	init_message_file(USER_LINKS, LIPATH, &ConfigFileEntry.linksfile);

	read_message_file(&ConfigFileEntry.motd);
	read_message_file(&ConfigFileEntry.opermotd);
	read_message_file(&ConfigFileEntry.linksfile);

	init_isupport();
}

/* initialize_server_capabs()
 *
 * inputs       - none
 * output       - none
 */
static void
initialize_server_capabs(void)
{
	add_capability("QS", CAP_QS, 1);
	add_capability("LL", CAP_LL, 1);
	add_capability("EOB", CAP_EOB, 1);
	if(ServerInfo.sid != NULL)	/* only enable TS6 if we have an SID */
		add_capability("TS6", CAP_TS6, 0);
	add_capability("ZIP", CAP_ZIP, 0);
	add_capability("CLUSTER", CAP_CLUSTER, 1);
}

/* write_pidfile()
 *
 * inputs       - filename+path of pid file
 * output       - NONE
 * side effects - write the pid of the ircd to filename
 */
static void
write_pidfile(const char *filename)
{
	FBFILE *fb;

	if((fb = fbopen(filename, "w")))
	{
		char buff[32];
		unsigned int pid = (unsigned int) getpid();
		size_t nbytes = ircsprintf(buff, "%u\n", pid);

		if((fbputs(buff, fb, nbytes) == -1))
			ilog(L_ERROR, "Error writing %u to pid file %s (%s)",
			     pid, filename, strerror(errno));

		fbclose(fb);
		return;
	}
	else
	{
		ilog(L_ERROR, "Error opening pid file %s", filename);
	}
}

/* check_pidfile()
 *
 * inputs       - filename+path of pid file
 * output       - none
 * side effects - reads pid from pidfile and checks if ircd is in process
 *                list. if it is, gracefully exits
 * -kre
 */
static void
check_pidfile(const char *filename)
{
#ifndef _WIN32
	FBFILE *fb;
	char buff[32];
	pid_t pidfromfile;

	/* Don't do logging here, since we don't have log() initialised */
	if((fb = fbopen(filename, "r")))
	{
		if(fbgets(buff, 20, fb) == NULL)
		{
			/* log(L_ERROR, "Error reading from pid file %s (%s)", filename,
			 * strerror(errno));
			 */
		}
		else
		{
			pidfromfile = atoi(buff);

			if(!kill(pidfromfile, 0))
			{
				/* log(L_ERROR, "Server is already running"); */
				printf("ircd: daemon is already running\n");
				exit(-1);
			}
		}

		fbclose(fb);
	}
	else if(errno != ENOENT)
	{
		/* log(L_ERROR, "Error opening pid file %s", filename); */
	}
#endif
}

/* setup_corefile()
 *
 * inputs       - nothing
 * output       - nothing
 * side effects - setups corefile to system limits.
 * -kre
 */
static void
setup_corefile(void)
{
#ifdef HAVE_SYS_RESOURCE_H
	struct rlimit rlim;	/* resource limits */

	/* Set corefilesize to maximum */
	if(!getrlimit(RLIMIT_CORE, &rlim))
	{
		rlim.rlim_cur = rlim.rlim_max;
		setrlimit(RLIMIT_CORE, &rlim);
	}
#endif
}

/* init_ssl()
 *
 * inputs       - nothing
 * output       - nothing
 * side effects - setups SSL context.
 */
static void
init_ssl(void)
{
#ifdef HAVE_LIBCRYPTO
	SSL_load_error_strings();
	SSLeay_add_ssl_algorithms();

	ServerInfo.ctx = SSL_CTX_new(SSLv23_server_method());
	if(!ServerInfo.ctx)
	{
		const char *s;

		fprintf(stderr, "ERROR: Could not initialize the SSL context -- %s\n",
			s = ERR_lib_error_string(ERR_get_error()));
		ilog(L_CRIT, "ERROR: Could not initialize the SSL context -- %s\n", s);
	}

	SSL_CTX_set_options(ServerInfo.ctx, SSL_OP_NO_SSLv2);
	SSL_CTX_set_options(ServerInfo.ctx, SSL_OP_TLS_ROLLBACK_BUG | SSL_OP_ALL);
	SSL_CTX_set_verify(ServerInfo.ctx, SSL_VERIFY_NONE, NULL);

	bio_spare_fd = save_spare_fd("SSL private key validation");
#endif /* HAVE_LIBCRYPTO */
}

/* init_callbacks()
 *
 * inputs       - nothing
 * output       - nothing
 * side effects - setups standard hook points
 */
static void
init_callbacks(void)
{
	iorecv_cb = register_callback("iorecv", iorecv_default);
	iosend_cb = register_callback("iosend", iosend_default);
	iorecvctrl_cb = register_callback("iorecvctrl", NULL);
	iosendctrl_cb = register_callback("iosendctrl", NULL);
}

int
main(int argc, char *argv[])
{
	/* Check to see if the user is running
	 * us as root, which is a nono
	 */
#ifndef _WIN32
	if(geteuid() == 0)
	{
		fprintf(stderr, "Don't run ircd as root!!!\n");
		return (-1);
	}

	/* Setup corefile size immediately after boot -kre */
	setup_corefile();

	/* set initialVMTop before we allocate any memory */
	initialVMTop = get_vm_top();
#endif

	/* save server boot time right away, so getrusage works correctly */
	set_time();

	/* It ain't random, but it ought to be a little harder to guess */
	srand(SystemTime.tv_sec ^ (SystemTime.tv_usec | (getpid() << 20)));
	memset(&me, 0, sizeof(me));
	memset(&meLocalUser, 0, sizeof(meLocalUser));
	me.localClient = &meLocalUser;
	dlinkAdd(&me, &me.node, &global_client_list);	/* Pointer to beginning
							   of Client list */

	memset(&ServerInfo, 0, sizeof(ServerInfo));

	/* Initialise the channel capability usage counts... */
	init_chcap_usage_counts();

	ConfigFileEntry.dpath = DPATH;
	ConfigFileEntry.configfile = CPATH;	/* Server configuration file */
	ConfigFileEntry.klinefile = KPATH;	/* Server kline file         */
	ConfigFileEntry.xlinefile = XPATH;	/* Server xline file         */
	ConfigFileEntry.rxlinefile = RXPATH;	/* Server regex xline file   */
	ConfigFileEntry.rklinefile = RKPATH;	/* Server regex kline file   */
	ConfigFileEntry.dlinefile = DLPATH;	/* dline file                */
	ConfigFileEntry.glinefile = GPATH;	/* gline log file            */
	ConfigFileEntry.cresvfile = CRESVPATH;	/* channel resv file      */
	ConfigFileEntry.nresvfile = NRESVPATH;	/* nick resv file         */
	myargv = argv;
	umask(077);		/* better safe than sorry --SRB */

	parseargs(&argc, &argv, myopts);

	if(printVersion)
	{
		printf("ircd: version %s(%s)\n", ircd_version, serno);
		exit(EXIT_SUCCESS);
	}

	if(chdir(ConfigFileEntry.dpath))
	{
		perror("chdir");
		exit(EXIT_FAILURE);
	}

	init_ssl();

#ifndef _WIN32
	if(!server_state.foreground)
	{
		make_daemon();
		close_standard_fds();	/* this needs to be before init_netio()! */
	}
	else
		print_startup(getpid());

	setup_signals();
#endif

	get_ircd_platform(ircd_platform);

	/* Init the event subsystem */
	eventInit();
	/* We need this to initialise the fd array before anything else */
	fdlist_init();
	init_log(logFileName);
	check_can_use_v6();
	init_comm();		/* This needs to be setup early ! -- adrian */
	/* Check if there is pidfile and daemon already running */
	check_pidfile(pidFileName);

#ifndef NOBALLOC
	initBlockHeap();
#endif
	init_dlink_nodes();
	init_callbacks();
	initialize_message_files();
	dbuf_init();
	init_hash();
	init_ip_hash_table();	/* client host ip hash table */
	init_host_hash();	/* Host-hashtable. */
	clear_tree_parse();
	init_client();
	init_class();
	init_whowas();
	init_stats();
	read_conf_files(1);	/* cold start init conf files */
	initServerMask();
	me.id[0] = '\0';
	init_uid();
	init_auth();		/* Initialise the auth code */
#ifndef _WIN32
	init_resolver();	/* Needs to be setup before the io loop */
#endif
	initialize_server_capabs();	/* Set up default_server_capabs */
	initialize_global_set_options();
	init_channels();
	init_cloak();

	if(ServerInfo.name == NULL)
	{
		ilog(L_CRIT, "No server name specified in serverinfo block.");
		exit(EXIT_FAILURE);
	}
	strlcpy(me.name, ServerInfo.name, sizeof(me.name));

	/* serverinfo{} description must exist.  If not, error out. */
	if(ServerInfo.description == NULL)
	{
		ilog(L_CRIT, "ERROR: No server description specified in serverinfo block.");
		exit(EXIT_FAILURE);
	}
	strlcpy(me.info, ServerInfo.description, sizeof(me.info));

	me.from = &me;
	me.servptr = &me;

	SetMe(&me);
	make_server(&me);

	me.lasttime = me.since = me.firsttime = CurrentTime;
	hash_add_client(&me);

	/* add ourselves to global_serv_list */
	dlinkAdd(&me, make_dlink_node(), &global_serv_list);

	check_class();

#ifndef STATIC_MODULES
	if(chdir(MODPATH))
	{
		ilog(L_CRIT, "Could not load core modules. Terminating!");
		exit(EXIT_FAILURE);
	}

	load_all_modules(1);
	load_core_modules(1);
	/* Go back to DPATH after checking to see if we can chdir to MODPATH */
	chdir(ConfigFileEntry.dpath);
	load_conf_modules();
#else
	load_all_modules(1);
#endif
	/*
	 * assemble_umode_buffer() has to be called after
	 * reading conf/loading modules.
	 */
	assemble_umode_buffer();

	write_pidfile(pidFileName);

	ilog(L_NOTICE, "Server Ready");

	eventAddIsh("cleanup_glines", cleanup_glines, NULL, CLEANUP_GLINES_TIME);
	eventAddIsh("cleanup_tklines", cleanup_tklines, NULL, CLEANUP_TKLINES_TIME);

	/* We want try_connections to be called as soon as possible now! -- adrian */
	/* No, 'cause after a restart it would cause all sorts of nick collides */
	eventAddIsh("try_connections", try_connections, NULL, STARTUP_CONNECTIONS_TIME);

	eventAddIsh("collect_zipstats", collect_zipstats, NULL, ZIPSTATS_TIME);

	/* Setup the timeout check. I'll shift it later :)  -- adrian */
	eventAddIsh("comm_checktimeouts", comm_checktimeouts, NULL, 1);

	if(ConfigServerHide.links_delay > 0)
		eventAddIsh("write_links_file", write_links_file, NULL,
			    ConfigServerHide.links_delay);
	else
		ConfigServerHide.links_disabled = 1;

	if(splitmode)
		eventAddIsh("check_splitmode", check_splitmode, NULL, 60);

	io_loop();
	return (0);
}
